1. Field of Invention
This invention relates to the reduction of leaves, pine needles, and small twigs, specifically to reduce labor time, garbage dump space and cost needed to dispose of said waste.
2. Description of Prior Art
Disposing of leaf waste matter has been an ongoing problem. Various methods have been employed for their disposal. Generally they are raked by hand into piles and inserted into plastic bags. These bags are then taken to garbage dumps. This has proven costly and time consuming. The environment has also been endangered as garbage dump space decreases.
The problem was partially solved with the implementation of mulching lawn mowers. This has been hindered by the cost of replacing an existing lawn mower with a new mulching mower. Also mulching lawn mowers are limited in their use. Leaf texture and thickness vary thus giving inconsistent and unsatisfactory results. The problem is aggravated further when the leaves become damp.
To provide a solution to the mentioned problems various inventors created attachments to be used with lawn mowers. In particular the simplest of these incorporates a method of blocking the discharge opening and constraining the residue in the mower housing to permit the blade to have a longer time to reduce the residue. Examples of this method are shown in the following U.S. patents.
U.S. Pat. No. 4,864,808 to Paker, 1980 Feb. 26, has no means to prevent the openings from becoming plugged when heavy concentrations of residue gather on the vent holes. Ventilation holes must remain open and be of sufficient size to allow the mower to operate properly. This is an increasingly important issue since more and more mowers are incorporating blades that are shaped to produce high air volume. The mulching grid in U.S. Pat. No. 4,306,409 to Wulfers, 1981 Dec 22, provides for ventilation with cleaning capability but the unconstrained motion of the flexible chain does not control the size of the ventilation openings, thus allowing uneven discharges to occur. Also the danger of blade and chain contact exists due to the flexible motion of the chains.
U.S. Pat. No. 4,864,808 to Weber, 1989 Sep. 12, uses a grid comprised of rods which pulverize leaves and lawn clippings into mulch. This is limited as the leaves must be spread evenly across the lawn to avoid clogging and thus having residue attach to the under side of the mower deck. Further the rods do not allow a cutting action in the event of small twigs and pine needles. U.S. Pat. No. 4,135,351 to Akgulian, 1979 Jan 23, incorporates an assembly having a mower housing in which air holes are offset in two plates. In order for this to work properly constant attention must be given to the vent holes as they become plugged. Also the aforementioned limitation on leaf thickness is a problem. In U.S. Pat. No. 4,890,446 to Isreal, 1990 Jan 2, an attachment is used limiting lawn debris to the under side of the mower deck. Again leaf thickness poses a threat to the effectiveness of this attachment. Also because of the vast variety of mower decks this attachment would require continual design changes. In U.S. Pat. No. 4,938,011 to Pernia, 1990 Jul 3, the problem also exists mower size and shape require a vast variety of design changes. U.S. Pat. No. 5,142,851 to Schueller, Nickel, and Rauwerdink, 1992 Sep 1, utilizes a post-processor having a housing in communication with the discharge chute of a lawn mower. The housing contains a blade which is operated by pulleys and a belt which is rotated by a pulley attached to the mower motor blade shaft. Due to the time involved in attaching the apparatus to the mower and that the belt is in the debris area, the practicality is considerably reduced. Also it limits the general public's ability to attach this themselves. And many mower motors do not have the space or the ability to utilize a second pulley that is needed to operate the secondary cutter blade.
In each of the above mentioned patents, there are several shortcomings and problems that need to be solved. First the simplicity with which a mulching attachment can be attached to a variety of lawn mowers, as well as use on lawn vacuums, thus allowing a person not skilled in mechanics to perform this. This in turn should allow simple removal as well. Second, the ability to cut debris as it exits the mower deck, thereby eliminating stress to the lawn mower engine. And it must do this regardless of conditions of the leaves, whether they are spread evenly across the lawn or in piles. Also the ability to cut pine needles and small twigs is needed to be an effective tool. This should prove to be the case even when leaves are wet. Third, clogging must be reduced to a minimum even under the aforementioned conditions.